(I) Although often referred to as tidal waves, a
tsunami is not a usual wave which is only much
bigger. (II) People unaware of the danger may
remain at the shore for collecting fish from the
exposed seabed. (III) Instead it is an endlessly
onrushing tide that forces its way through any
obstacle. (IV) Most of the damage is caused by
the huge mass of water behind the initial wave
front. (V) The sheer weight of water is enough
to pulverize objects in its path, often reducing
buildings to their foundations.

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II III IV V

2. Ants

(I) Like many insects, ants have six legs. (II) An
ant colony consists of the queen ant, workers,
soldiers and males. (III) They are very strong so
they can run very quickly. (IV) If a man could
run as fast for his size as an ant can, he could
run as fast as a racehorse. (V) Although many
ants are tiny and only three millimeters long
they can lift 20 times their own body weight.

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II III IV V

3. Practice of Medicine

(I) Rainforests are extremely important in the
ecology of the Earth. (II) They cover about 7%
of the Earth's surface and are havens for
millions of plants and animals. (III) The plants of
the rainforests generate much of the Earth's
oxygen and remove carbon dioxide from the
atmosphere. (IV) There are many types of
tropical rainforests in the world. (V) However
these plants are also very important to people in
other ways; many are used in new drugs that
fight disease and illness.